CASE 580SM Series 3 w/ Powershift trans

[Pocho86]

This is in regards to the Powershift transmission 4 Wheel Drive.

I have constant power at the 4WD solenoid approx 2-3 seconds after unit starts up.

The way it works for those not familiar with system on any backhoe trans power shift or standard, 4WD Solenoid Powered = 2WD, Unpowered = 4WD.

I have no error codes. I believe I either have a harness or controller issue, but honestly not sure.

I have power "on and off with the switch" at the 4WD switch on wire 25E which changed into 25C at the side console harness and then goes to the TCM. From the switch 25E to the side console harness pin E6 its good. From the side console harness to the TCM I didn't have anything, I actually have a wiring discrepancy there because its 25E on the console side but on the outside it isnt 25C like its supposed to be, im actually unable to idenfiy what that wire is. So, I cut the wire at the side console harness from the 4wd switch and ran a jumper directly from the 4wd switch to the TCM to pin 22 and still no change.

From TCM pin 39 wire 25X it goes to J1 Floor Connector then to 4WD Solenoid. That wire ohms out good.

Were im at right now is, I do know the TCM is commanding the power to the solenoid to put it into 2wd but I dont know if something in the system is commanding it too or if i have a wiring fault or if the TCM is faulty.

I disconnected the brake pressure switches and no change.

Any help is appreciated

 

[Coy Lancaster]

Did your switch test out as being good?

 

[Pocho86]

Did your switch test out as being good?

If your talking about the 4wd drive switch, yes that is good.

 

[Coy Lancaster]

When I worked for the local Case dealer when the "M" series came out there were some issues at the main harness junction below the loader control tower where harness came up through the floor and connected to cab harness. The issues were loose pins and sockets, burnt wires and chaffed wires. You may want to check there, just a thought.

 

[Pocho86]

Yeah I used to work for the case dealer as well for about 8 years. the M series 2 and M series 3 powershift transmission electrical and transmissions are set up different, different control modules and different style transmissions and the series 3 and N series are different as well. I pretty much went through everything and don’t understand why the controller is signaling power to the four-wheel-drive solenoid which turns the four-wheel-drive off no matter if the switch is in on or off positions. it’s almost like either the modules faulty or something is signaling it to turn on. Yeah I used to work for the case dealer as well the M series 2 and M series 3 powershift transmissions are set up different different control modules and different style transmissions and the series 3 from the end series are different as well I pretty much went through everything and don’t understand why the controller is signaling power to the four-wheel-drive solenoid which turns the four-wheel-drive off no matter if the switch is in on or off position it’s almost like either the modules faulty or something is signaling it to turn on. I even cut the wire at the tcm from the switch and still have solenoid power which by right should be off...

 

[Coy Lancaster]

Sounds like you may have a problem in the harness or one of the connectors with a rubbed wire and bleeding over to 4wd solenoid.